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WorksheetsChapter 3 Review — Hair
Total questions: 26
Worksheet time: 21mins
The shaft of the hair is considered class evidence in a trial.
True
False
Hair is composed of a protein called cellulose.
True
False
All hairs on the head of a person are identical.
True
False
The cortex may contain pigment granules.
True
False
The hair shaft is composed of the cuticle, cortex, and ___________.
medulla
root
crown
granules
Which factors are used to calculate the medullary index of the hair?
scale diameter of cuticle and the length of the hair
width of cortex and the width of the medulla
length of entire hair and the pattern of pigmentation
diameter of medulla and the diameter of the hair
Which of the following characteristics is found in typical Asian hair?
dark medulla
sparsely distributed pigment granules
flattened cross section
hair is curly
Human hair has which type of cuticle?
imbricate
spinous
coronal
pigmented
Neutron activation analysis can check hair for the presence of _________.
DNA
arsenic
water content
hair dye
Which part(s) of a hair can be analyzed for DNA?
root
cuticle
medulla
cortex
shaft
The period of active hair growth is called the _____ stage.
catagen
telogen
anagen
imagen
Although variations can occur, which of the following best describes European hair?
kinky with dense, unevenly distributed pigment
straight with evenly distributed granules
round cross section with a large diameter
coarse with a thick cuticle and a continuous medulla
Which of the following is most likely a result of hair bleaching?
increased number of disulfide bonds
a yellowish tint to the hair
a more triangular cross section
thickened scales on the cuticle
Reorder the stages of hair growth
anagen
catagen
telogen
Why is hair considered class evidence?
Draw and label the 3 main layers of the hair shaft.
Crime-scene investigators must determine if a collected hair is human or animal. Select all characteristics that typically indicate animal hair rather than human hair.
a medullary index that is generally greater than 0.5
Unique medulla (scales, ladder pattern, etc.)
imbricate cuticle scales typical of humans
coronal or spinous cuticle types common in many animals
Calculate the medullary index of a hair whose diameter is 110 microns and whose medulla measures 58 microns. Is this a human or animal hair?
0.53 and animal hair
0.53 and human hair
1.9 and human hair
1.9 and animal hair
At a burglary crime scene, long hairs were found attached to a broken safe lock. Police request 25 to 50 hairs from a suspect and specify that the hairs must be pulled rather than cut. Why must the hairs be pulled?
Pulled hairs include roots and follicular tissue that can provide DNA
Pulled hairs are longer and easier to compare microscopically
Pulled hairs prevent damage to the cuticle scales
Pulled hairs ensure the sample is not from a wig
Why is it necessary to obtain 25 to 50 hairs from the suspect?
To capture natural variation in a person’s hair and obtain a representative sample
To allow chemical testing to consume minimal material
To reduce the chance of contamination from collection tools
To ensure only growing hairs are sampled
The suspect denies current drug use and claims she stopped one year ago. How can police determine whether she has been off drugs for over one year using her long hair?
By segmental analysis of the hair along its length, correlating drug presence to growth rate over time
By testing only the hair root; drug use is stored there indefinitely
By examining cuticle scale patterns; they reveal drug timelines
By checking hair color changes; bleaching indicates recent drug use
Suppose the suspect’s hairs match the hairs found at the crime scene. Why does this not necessarily prove she was the guilty party?
Hair is class evidence; many people can share similar microscopic characteristics
Hair always transfers secondarily in public places
Hair cannot be compared microscopically
Hair from different body areas is identical for all people
Which of the following is NOT a layer of the hair shaft?
cuticle
follicle
cortex
medulla
Match the following
the central core of the hair shaft that may be absent in some species
medulla
the protein rich structure around the central core of the hair shaft that contains pigment
cortex
the outer covering of the hair shaft that is composed of overlapping scales
cuticle
Match the following hair cross sections with their ethnicity
Caucasian/European hair
Asian hair
African hair
Which of the following cannot be determined with microscopic examination of hair?
whether a hair came from a 25-year old or and infant
whether a hair is from a man or woman
whether a hair is from a scalp or a beard
whether the hair is consistent with European or Asian descent
